Yeast mitochondrial DNA polymerase is a highly processive single-subunit enzyme

Katrin Viikov; Priit Väljamäe; Juhan Sedman

doi:10.1016/j.mito.2010.08.007

Yeast mitochondrial DNA polymerase is a highly processive single-subunit enzyme

Mitochondrion. 2011 Jan;11(1):119-26. doi: 10.1016/j.mito.2010.08.007. Epub 2010 Aug 31.

Authors

Katrin Viikov¹, Priit Väljamäe, Juhan Sedman

Affiliation

¹ Department of Biochemistry, Institute of Molecular and Cell Biology, University of Tartu, Vanemuise 46, Tartu 51014, Estonia.

PMID: 20807588
DOI: 10.1016/j.mito.2010.08.007

Abstract

Polymerase γ is solely responsible for fast and faithful replication of the mitochondrial genome. High processivity of the polymerase γ is often achieved by association of the catalytic subunit with accessory factors that enhance its catalytic activity and/or DNA binding. Here we characterize the intrinsic catalytic activity and processivity of the recombinant catalytic subunit of yeast polymerase γ, the Mip1 protein. We demonstrate that Mip1 can efficiently synthesize DNA stretches of up to several thousand nucleotides without dissociation from the template. Furthermore, we show that Mip1 can perform DNA synthesis on double-stranded templates utilizing a strand displacement mechanism. Our observations confirm that in contrast to its homologues in other organisms, Mip1 can function as a single-subunit replicative polymerase.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Catalytic Domain
DNA Polymerase I / chemistry
DNA Polymerase I / genetics
DNA Polymerase I / isolation & purification
DNA Polymerase I / metabolism*
DNA Replication
DNA, Mitochondrial / genetics
DNA, Mitochondrial / metabolism*
DNA-Directed DNA Polymerase / chemistry
DNA-Directed DNA Polymerase / genetics
DNA-Directed DNA Polymerase / metabolism
Mitochondria / enzymology*
Protein Subunits / chemistry
Protein Subunits / genetics
Protein Subunits / metabolism*
Recombinant Proteins / chemistry
Recombinant Proteins / genetics
Recombinant Proteins / isolation & purification
Recombinant Proteins / metabolism
Saccharomyces cerevisiae / enzymology*
Saccharomyces cerevisiae / genetics
Saccharomyces cerevisiae / metabolism
Saccharomyces cerevisiae Proteins / chemistry
Saccharomyces cerevisiae Proteins / genetics
Saccharomyces cerevisiae Proteins / isolation & purification
Saccharomyces cerevisiae Proteins / metabolism*

Substances

DNA, Mitochondrial
Protein Subunits
Recombinant Proteins
Saccharomyces cerevisiae Proteins
DNA Polymerase I
DNA-Directed DNA Polymerase
MIP1 protein, S cerevisiae